Epileptic spasms in the acute phase of pediatric anti-N-methyl-d-aspartate receptor encephalitis: a case series.

Background: Anti-N-methyl-D-aspartate receptor encephalitis (NMDARE) is an autoimmune disorder characterized by a broad spectrum of neuropsychiatric symptoms. Epileptic seizures are among the most common clinical manifestations, occurring in approximately 25% of patients. However, epileptic spasms as a distinct seizure type in the acute phase of NMDARE have rarely been documented. Case presentation: We reported three pediatric patients who developed epileptic spasms during the acute phase of NMDARE. The cohort included two females and one male, with age at onset ranging from 9 months to 9 years. Epileptic spasms emerged within one month of disease onset and were accompanied by focal seizures in all cases. Electroencephalography (EEG) monitored frequent epileptic spasms in all three children. Brain magnetic resonance imaging (MRI) revealed bilateral frontal lobe lesions in two patients. Following combined immunotherapy of intravenous immunoglobulin plus methylprednisolone or therapeutic plasma exchange, one patient discontinued treatment, one experienced recurrence two years later, and one showed favorable recovery at the last follow-up of five months. Conclusion: This case series highlights epileptic spasms as a notable and less common clinical phenotype in the acute stage of NMDARE. Our findings broaden the recognized clinical spectrum of the NMDARE and offer practical insights for diagnosis and management in pediatric practice.